| Message ID | 20230321183342.617114-2-aleksandr.mikhalitsyn@canonical.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | Add SCM_PIDFD and SO_PEERPIDFD | expand |
From: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> Date: Tue, 21 Mar 2023 19:33:40 +0100 > Implement SCM_PIDFD, a new type of CMSG type analogical to SCM_CREDENTIALS, > but it contains pidfd instead of plain pid, which allows programmers not > to care about PID reuse problem. > > Idea comes from UAPI kernel group: > https://uapi-group.org/kernel-features/ > > Big thanks to Christian Brauner and Lennart Poettering for productive > discussions about this. > > Cc: "David S. Miller" <davem@davemloft.net> > Cc: Eric Dumazet <edumazet@google.com> > Cc: Jakub Kicinski <kuba@kernel.org> > Cc: Paolo Abeni <pabeni@redhat.com> > Cc: Leon Romanovsky <leon@kernel.org> > Cc: David Ahern <dsahern@kernel.org> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Kees Cook <keescook@chromium.org> > Cc: Christian Brauner <brauner@kernel.org> > Cc: Kuniyuki Iwashima <kuniyu@amazon.com> > Cc: Lennart Poettering <mzxreary@0pointer.de> > Cc: linux-kernel@vger.kernel.org > Cc: netdev@vger.kernel.org > Cc: linux-arch@vger.kernel.org > Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Thanks, Kuniyuki
Hi Alexander,
Thank you for the patch! Yet something to improve:
[auto build test ERROR on net-next/main]
url: https://github.com/intel-lab-lkp/linux/commits/Alexander-Mikhalitsyn/scm-add-SO_PASSPIDFD-and-SCM_PIDFD/20230322-024808
patch link: https://lore.kernel.org/r/20230321183342.617114-2-aleksandr.mikhalitsyn%40canonical.com
patch subject: [PATCH net-next v2 1/3] scm: add SO_PASSPIDFD and SCM_PIDFD
config: arm-allmodconfig (https://download.01.org/0day-ci/archive/20230322/202303222101.avwNiFWQ-lkp@intel.com/config)
compiler: arm-linux-gnueabi-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/491b69039f4479e1e0fb3af635c96989cdd23734
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review Alexander-Mikhalitsyn/scm-add-SO_PASSPIDFD-and-SCM_PIDFD/20230322-024808
git checkout 491b69039f4479e1e0fb3af635c96989cdd23734
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arm olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202303222101.avwNiFWQ-lkp@intel.com/
All errors (new ones prefixed by >>, old ones prefixed by <<):
>> ERROR: modpost: "pidfd_create" [net/unix/unix.ko] undefined!
On Tue, Mar 21, 2023 at 07:33:40PM +0100, Alexander Mikhalitsyn wrote: > Implement SCM_PIDFD, a new type of CMSG type analogical to SCM_CREDENTIALS, > but it contains pidfd instead of plain pid, which allows programmers not > to care about PID reuse problem. > > Idea comes from UAPI kernel group: > https://uapi-group.org/kernel-features/ > > Big thanks to Christian Brauner and Lennart Poettering for productive > discussions about this. > > Cc: "David S. Miller" <davem@davemloft.net> > Cc: Eric Dumazet <edumazet@google.com> > Cc: Jakub Kicinski <kuba@kernel.org> > Cc: Paolo Abeni <pabeni@redhat.com> > Cc: Leon Romanovsky <leon@kernel.org> > Cc: David Ahern <dsahern@kernel.org> > Cc: Arnd Bergmann <arnd@arndb.de> > Cc: Kees Cook <keescook@chromium.org> > Cc: Christian Brauner <brauner@kernel.org> > Cc: Kuniyuki Iwashima <kuniyu@amazon.com> > Cc: Lennart Poettering <mzxreary@0pointer.de> > Cc: linux-kernel@vger.kernel.org > Cc: netdev@vger.kernel.org > Cc: linux-arch@vger.kernel.org > Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> > --- > v2: > According to review comments from Kuniyuki Iwashima and Christian Brauner: > - use pidfd_create(..) retval as a result > - whitespace change > --- > arch/alpha/include/uapi/asm/socket.h | 2 ++ > arch/mips/include/uapi/asm/socket.h | 2 ++ > arch/parisc/include/uapi/asm/socket.h | 2 ++ > arch/sparc/include/uapi/asm/socket.h | 2 ++ > include/linux/net.h | 1 + > include/linux/socket.h | 1 + > include/net/scm.h | 14 ++++++++++++-- > include/uapi/asm-generic/socket.h | 2 ++ > net/core/sock.c | 11 +++++++++++ > net/mptcp/sockopt.c | 1 + > net/unix/af_unix.c | 18 +++++++++++++----- > tools/include/uapi/asm-generic/socket.h | 2 ++ > 12 files changed, 51 insertions(+), 7 deletions(-) > > diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h > index 739891b94136..ff310613ae64 100644 > --- a/arch/alpha/include/uapi/asm/socket.h > +++ b/arch/alpha/include/uapi/asm/socket.h > @@ -137,6 +137,8 @@ > > #define SO_RCVMARK 75 > > +#define SO_PASSPIDFD 76 > + > #if !defined(__KERNEL__) > > #if __BITS_PER_LONG == 64 > diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h > index 18f3d95ecfec..762dcb80e4ec 100644 > --- a/arch/mips/include/uapi/asm/socket.h > +++ b/arch/mips/include/uapi/asm/socket.h > @@ -148,6 +148,8 @@ > > #define SO_RCVMARK 75 > > +#define SO_PASSPIDFD 76 > + > #if !defined(__KERNEL__) > > #if __BITS_PER_LONG == 64 > diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h > index f486d3dfb6bb..df16a3e16d64 100644 > --- a/arch/parisc/include/uapi/asm/socket.h > +++ b/arch/parisc/include/uapi/asm/socket.h > @@ -129,6 +129,8 @@ > > #define SO_RCVMARK 0x4049 > > +#define SO_PASSPIDFD 0x404A > + > #if !defined(__KERNEL__) > > #if __BITS_PER_LONG == 64 > diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h > index 2fda57a3ea86..6e2847804fea 100644 > --- a/arch/sparc/include/uapi/asm/socket.h > +++ b/arch/sparc/include/uapi/asm/socket.h > @@ -130,6 +130,8 @@ > > #define SO_RCVMARK 0x0054 > > +#define SO_PASSPIDFD 0x0055 > + > #if !defined(__KERNEL__) > > > diff --git a/include/linux/net.h b/include/linux/net.h > index b73ad8e3c212..c234dfbe7a30 100644 > --- a/include/linux/net.h > +++ b/include/linux/net.h > @@ -43,6 +43,7 @@ struct net; > #define SOCK_PASSSEC 4 > #define SOCK_SUPPORT_ZC 5 > #define SOCK_CUSTOM_SOCKOPT 6 > +#define SOCK_PASSPIDFD 7 > > #ifndef ARCH_HAS_SOCKET_TYPES > /** > diff --git a/include/linux/socket.h b/include/linux/socket.h > index 13c3a237b9c9..6bf90f251910 100644 > --- a/include/linux/socket.h > +++ b/include/linux/socket.h > @@ -177,6 +177,7 @@ static inline size_t msg_data_left(struct msghdr *msg) > #define SCM_RIGHTS 0x01 /* rw: access rights (array of int) */ > #define SCM_CREDENTIALS 0x02 /* rw: struct ucred */ > #define SCM_SECURITY 0x03 /* rw: security label */ > +#define SCM_PIDFD 0x04 /* ro: pidfd (int) */ > > struct ucred { > __u32 pid; > diff --git a/include/net/scm.h b/include/net/scm.h > index 585adc1346bd..0c717ae9c8db 100644 > --- a/include/net/scm.h > +++ b/include/net/scm.h > @@ -124,8 +124,9 @@ static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg, > struct scm_cookie *scm, int flags) > { > if (!msg->msg_control) { > - if (test_bit(SOCK_PASSCRED, &sock->flags) || scm->fp || > - scm_has_secdata(sock)) > + if (test_bit(SOCK_PASSCRED, &sock->flags) || > + test_bit(SOCK_PASSPIDFD, &sock->flags) || > + scm->fp || scm_has_secdata(sock)) > msg->msg_flags |= MSG_CTRUNC; > scm_destroy(scm); > return; > @@ -141,6 +142,15 @@ static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg, > put_cmsg(msg, SOL_SOCKET, SCM_CREDENTIALS, sizeof(ucreds), &ucreds); > } > > + if (test_bit(SOCK_PASSPIDFD, &sock->flags)) { > + int pidfd; > + > + WARN_ON_ONCE(!scm->pid); > + pidfd = pidfd_create(scm->pid, 0); > + > + put_cmsg(msg, SOL_SOCKET, SCM_PIDFD, sizeof(int), &pidfd); So here we need to also make sure that we can't end up in a situation where the receiver gets an error message and discards the message but we've snuck an fd into their fdtable. So callers of scm_recv() should be in a path where the message can't fail anymore and we're about to return to userspace.
diff --git a/arch/alpha/include/uapi/asm/socket.h b/arch/alpha/include/uapi/asm/socket.h index 739891b94136..ff310613ae64 100644 --- a/arch/alpha/include/uapi/asm/socket.h +++ b/arch/alpha/include/uapi/asm/socket.h @@ -137,6 +137,8 @@ #define SO_RCVMARK 75 +#define SO_PASSPIDFD 76 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 diff --git a/arch/mips/include/uapi/asm/socket.h b/arch/mips/include/uapi/asm/socket.h index 18f3d95ecfec..762dcb80e4ec 100644 --- a/arch/mips/include/uapi/asm/socket.h +++ b/arch/mips/include/uapi/asm/socket.h @@ -148,6 +148,8 @@ #define SO_RCVMARK 75 +#define SO_PASSPIDFD 76 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 diff --git a/arch/parisc/include/uapi/asm/socket.h b/arch/parisc/include/uapi/asm/socket.h index f486d3dfb6bb..df16a3e16d64 100644 --- a/arch/parisc/include/uapi/asm/socket.h +++ b/arch/parisc/include/uapi/asm/socket.h @@ -129,6 +129,8 @@ #define SO_RCVMARK 0x4049 +#define SO_PASSPIDFD 0x404A + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 diff --git a/arch/sparc/include/uapi/asm/socket.h b/arch/sparc/include/uapi/asm/socket.h index 2fda57a3ea86..6e2847804fea 100644 --- a/arch/sparc/include/uapi/asm/socket.h +++ b/arch/sparc/include/uapi/asm/socket.h @@ -130,6 +130,8 @@ #define SO_RCVMARK 0x0054 +#define SO_PASSPIDFD 0x0055 + #if !defined(__KERNEL__) diff --git a/include/linux/net.h b/include/linux/net.h index b73ad8e3c212..c234dfbe7a30 100644 --- a/include/linux/net.h +++ b/include/linux/net.h @@ -43,6 +43,7 @@ struct net; #define SOCK_PASSSEC 4 #define SOCK_SUPPORT_ZC 5 #define SOCK_CUSTOM_SOCKOPT 6 +#define SOCK_PASSPIDFD 7 #ifndef ARCH_HAS_SOCKET_TYPES /** diff --git a/include/linux/socket.h b/include/linux/socket.h index 13c3a237b9c9..6bf90f251910 100644 --- a/include/linux/socket.h +++ b/include/linux/socket.h @@ -177,6 +177,7 @@ static inline size_t msg_data_left(struct msghdr *msg) #define SCM_RIGHTS 0x01 /* rw: access rights (array of int) */ #define SCM_CREDENTIALS 0x02 /* rw: struct ucred */ #define SCM_SECURITY 0x03 /* rw: security label */ +#define SCM_PIDFD 0x04 /* ro: pidfd (int) */ struct ucred { __u32 pid; diff --git a/include/net/scm.h b/include/net/scm.h index 585adc1346bd..0c717ae9c8db 100644 --- a/include/net/scm.h +++ b/include/net/scm.h @@ -124,8 +124,9 @@ static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg, struct scm_cookie *scm, int flags) { if (!msg->msg_control) { - if (test_bit(SOCK_PASSCRED, &sock->flags) || scm->fp || - scm_has_secdata(sock)) + if (test_bit(SOCK_PASSCRED, &sock->flags) || + test_bit(SOCK_PASSPIDFD, &sock->flags) || + scm->fp || scm_has_secdata(sock)) msg->msg_flags |= MSG_CTRUNC; scm_destroy(scm); return; @@ -141,6 +142,15 @@ static __inline__ void scm_recv(struct socket *sock, struct msghdr *msg, put_cmsg(msg, SOL_SOCKET, SCM_CREDENTIALS, sizeof(ucreds), &ucreds); } + if (test_bit(SOCK_PASSPIDFD, &sock->flags)) { + int pidfd; + + WARN_ON_ONCE(!scm->pid); + pidfd = pidfd_create(scm->pid, 0); + + put_cmsg(msg, SOL_SOCKET, SCM_PIDFD, sizeof(int), &pidfd); + } + scm_destroy_cred(scm); scm_passec(sock, msg, scm); diff --git a/include/uapi/asm-generic/socket.h b/include/uapi/asm-generic/socket.h index 638230899e98..b76169fdb80b 100644 --- a/include/uapi/asm-generic/socket.h +++ b/include/uapi/asm-generic/socket.h @@ -132,6 +132,8 @@ #define SO_RCVMARK 75 +#define SO_PASSPIDFD 76 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 || (defined(__x86_64__) && defined(__ILP32__)) diff --git a/net/core/sock.c b/net/core/sock.c index c25888795390..3f974246ba3e 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1246,6 +1246,13 @@ int sk_setsockopt(struct sock *sk, int level, int optname, clear_bit(SOCK_PASSCRED, &sock->flags); break; + case SO_PASSPIDFD: + if (valbool) + set_bit(SOCK_PASSPIDFD, &sock->flags); + else + clear_bit(SOCK_PASSPIDFD, &sock->flags); + break; + case SO_TIMESTAMP_OLD: case SO_TIMESTAMP_NEW: case SO_TIMESTAMPNS_OLD: @@ -1737,6 +1744,10 @@ int sk_getsockopt(struct sock *sk, int level, int optname, v.val = !!test_bit(SOCK_PASSCRED, &sock->flags); break; + case SO_PASSPIDFD: + v.val = !!test_bit(SOCK_PASSPIDFD, &sock->flags); + break; + case SO_PEERCRED: { struct ucred peercred; diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c index 8a9656248b0f..bd80e707d0b3 100644 --- a/net/mptcp/sockopt.c +++ b/net/mptcp/sockopt.c @@ -355,6 +355,7 @@ static int mptcp_setsockopt_sol_socket(struct mptcp_sock *msk, int optname, case SO_BROADCAST: case SO_BSDCOMPAT: case SO_PASSCRED: + case SO_PASSPIDFD: case SO_PASSSEC: case SO_RXQ_OVFL: case SO_WIFI_STATUS: diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 0b0f18ecce44..b0ac768752fa 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -1361,7 +1361,8 @@ static int unix_dgram_connect(struct socket *sock, struct sockaddr *addr, if (err) goto out; - if (test_bit(SOCK_PASSCRED, &sock->flags) && + if ((test_bit(SOCK_PASSCRED, &sock->flags) || + test_bit(SOCK_PASSPIDFD, &sock->flags)) && !unix_sk(sk)->addr) { err = unix_autobind(sk); if (err) @@ -1469,7 +1470,8 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr, if (err) goto out; - if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr) { + if ((test_bit(SOCK_PASSCRED, &sock->flags) || + test_bit(SOCK_PASSPIDFD, &sock->flags)) && !u->addr) { err = unix_autobind(sk); if (err) goto out; @@ -1670,6 +1672,8 @@ static void unix_sock_inherit_flags(const struct socket *old, { if (test_bit(SOCK_PASSCRED, &old->flags)) set_bit(SOCK_PASSCRED, &new->flags); + if (test_bit(SOCK_PASSPIDFD, &old->flags)) + set_bit(SOCK_PASSPIDFD, &new->flags); if (test_bit(SOCK_PASSSEC, &old->flags)) set_bit(SOCK_PASSSEC, &new->flags); } @@ -1819,8 +1823,10 @@ static bool unix_passcred_enabled(const struct socket *sock, const struct sock *other) { return test_bit(SOCK_PASSCRED, &sock->flags) || + test_bit(SOCK_PASSPIDFD, &sock->flags) || !other->sk_socket || - test_bit(SOCK_PASSCRED, &other->sk_socket->flags); + test_bit(SOCK_PASSCRED, &other->sk_socket->flags) || + test_bit(SOCK_PASSPIDFD, &other->sk_socket->flags); } /* @@ -1922,7 +1928,8 @@ static int unix_dgram_sendmsg(struct socket *sock, struct msghdr *msg, goto out; } - if (test_bit(SOCK_PASSCRED, &sock->flags) && !u->addr) { + if ((test_bit(SOCK_PASSCRED, &sock->flags) || + test_bit(SOCK_PASSPIDFD, &sock->flags)) && !u->addr) { err = unix_autobind(sk); if (err) goto out; @@ -2824,7 +2831,8 @@ static int unix_stream_read_generic(struct unix_stream_read_state *state, /* Never glue messages from different writers */ if (!unix_skb_scm_eq(skb, &scm)) break; - } else if (test_bit(SOCK_PASSCRED, &sock->flags)) { + } else if (test_bit(SOCK_PASSCRED, &sock->flags) || + test_bit(SOCK_PASSPIDFD, &sock->flags)) { /* Copy credentials */ scm_set_cred(&scm, UNIXCB(skb).pid, UNIXCB(skb).uid, UNIXCB(skb).gid); unix_set_secdata(&scm, skb); diff --git a/tools/include/uapi/asm-generic/socket.h b/tools/include/uapi/asm-generic/socket.h index 8756df13be50..fbbc4bf53ee3 100644 --- a/tools/include/uapi/asm-generic/socket.h +++ b/tools/include/uapi/asm-generic/socket.h @@ -121,6 +121,8 @@ #define SO_RCVMARK 75 +#define SO_PASSPIDFD 76 + #if !defined(__KERNEL__) #if __BITS_PER_LONG == 64 || (defined(__x86_64__) && defined(__ILP32__))
Implement SCM_PIDFD, a new type of CMSG type analogical to SCM_CREDENTIALS, but it contains pidfd instead of plain pid, which allows programmers not to care about PID reuse problem. Idea comes from UAPI kernel group: https://uapi-group.org/kernel-features/ Big thanks to Christian Brauner and Lennart Poettering for productive discussions about this. Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Leon Romanovsky <leon@kernel.org> Cc: David Ahern <dsahern@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Kees Cook <keescook@chromium.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Kuniyuki Iwashima <kuniyu@amazon.com> Cc: Lennart Poettering <mzxreary@0pointer.de> Cc: linux-kernel@vger.kernel.org Cc: netdev@vger.kernel.org Cc: linux-arch@vger.kernel.org Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> --- v2: According to review comments from Kuniyuki Iwashima and Christian Brauner: - use pidfd_create(..) retval as a result - whitespace change --- arch/alpha/include/uapi/asm/socket.h | 2 ++ arch/mips/include/uapi/asm/socket.h | 2 ++ arch/parisc/include/uapi/asm/socket.h | 2 ++ arch/sparc/include/uapi/asm/socket.h | 2 ++ include/linux/net.h | 1 + include/linux/socket.h | 1 + include/net/scm.h | 14 ++++++++++++-- include/uapi/asm-generic/socket.h | 2 ++ net/core/sock.c | 11 +++++++++++ net/mptcp/sockopt.c | 1 + net/unix/af_unix.c | 18 +++++++++++++----- tools/include/uapi/asm-generic/socket.h | 2 ++ 12 files changed, 51 insertions(+), 7 deletions(-)